Android加载时显示Splash-Screen [英] Android display Splash-Screen while loading

问题描述

我有一个Android应用程序，显示启动画面3秒钟。之后，MainActivity被加载。

I have an Android App, which shows a "Splash Screen" for 3 seconds. After that, the MainActivity gets loaded.

不幸的是，MainActivity需要额外的~4秒才能加载。在第一次启动时甚至更长。但是当加载App时，一切都运行顺畅。

Unfortunately the MainActivity takes additional ~4 seconds to load. On first startup even longer. However when the App is loaded, everything runs smooth.

现在，在Splash Screen的显示过程中，如何实现MainActivity的加载？它应该显示一个图像，直到整个东西完全加载。
我已经阅读了有关Async-Task的内容，但我不知道该放在哪里以及如何正确使用它。有人可以帮帮我吗？

Now how can I achieve it, that the MainActivity gets loaded, during the display of the Splash Screen? It just should display an image until the whole thing loaded completely. I have read about Async-Task, but I'm not sure where to put it and how to use it properly. Can someone help me please?

SplashScreen.java

public class SplashScreen extends Activity {
    private static int SPLASH_TIME_OUT = 3000;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_startup);

        new Handler().postDelayed(new Runnable() {
            @Override
            public void run() {
                Intent i = new Intent(SplashScreen.this, MainActivity.class);
                startActivity(i);
                finish();
            }
        }, SPLASH_TIME_OUT);
    }
}

MainActivity.java

public class MainActivity extends Activity implements OnClickListener, MediaController.MediaPlayerControl {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        //Some heavy processing
        //starting services
        //starting Google Text to Speech
        //and so on...

    }

}

推荐答案

如果没有关于启动屏幕显示时间的具体限制，您可以通过以下方式使用 AsyncTask ：

If there are no specific constraints about the time the splash screen should be shown, you could use the AsyncTask in the following way:

public class SplashScreen extends Activity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_startup);
        startHeavyProcessing();

    }

    private void startHeavyProcessing(){
       new LongOperation().execute("");
    }

    private class LongOperation extends AsyncTask<String, Void, String> {

        @Override
        protected String doInBackground(String... params) {
            //some heavy processing resulting in a Data String
            for (int i = 0; i < 5; i++) {
                try {
                    Thread.sleep(1000);
                } catch (InterruptedException e) {
                    Thread.interrupted();
                }
            }
            return "whatever result you have";
        }

        @Override
        protected void onPostExecute(String result) {
            Intent i = new Intent(SplashScreen.this, MainActivity.class);
            i.putExtra("data", result);
            startActivity(i);
            finish();
        }

        @Override
        protected void onPreExecute() {}

        @Override
        protected void onProgressUpdate(Void... values) {}
    }
}

如果结果数据的性质不同于你可以将一个 Parcelable 对象作为一个字符串作为你的活动的额外内容。在 onCreate 中，您可以使用以下方法检索数据：

If the resulting data if of another nature than a String you could put a Parcelable Object as an extra to your activity. In onCreate you can retrieve the data with:

getIntent（）。getExtras.getString （'数据'）;

这篇关于Android加载时显示Splash-Screen的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！